1,490 research outputs found

    Shaping educational attitudes and aspirations: the influence of parents, place and poverty: stage 1 report

    Get PDF
    An interim report of a study which aims to better understand the relationship between children’s aspirations in relation to education and employment, and the context in which they are formed. In particular, the study seeks to explore how parental circumstances and attitudes, the school as an institution, and the opportunity structures of the neighbourhood come together to shape aspirations in deprived urban areas. This report examines: • The assumptions of current policy that aspirations are a key ingredient of educational and labour market outcomes; • What aspirations are and how they can be understood; • What young people’s aspirations are for further and higher education and for future occupations in three secondary schools; • The main influences on those aspirations, including the roles of parents, schools and the neighbourhood context • Messages for the second stage of the research and emerging lessons for policy. The report provides some evidence to question the assumption among policy makers that there is a ‘poverty of aspirations’ among young people from disadvantaged backgrounds or living in disadvantaged neighbourhoods

    Algorithms to automatically quantify the geometric similarity of anatomical surfaces

    Full text link
    We describe new approaches for distances between pairs of 2-dimensional surfaces (embedded in 3-dimensional space) that use local structures and global information contained in inter-structure geometric relationships. We present algorithms to automatically determine these distances as well as geometric correspondences. This is motivated by the aspiration of students of natural science to understand the continuity of form that unites the diversity of life. At present, scientists using physical traits to study evolutionary relationships among living and extinct animals analyze data extracted from carefully defined anatomical correspondence points (landmarks). Identifying and recording these landmarks is time consuming and can be done accurately only by trained morphologists. This renders these studies inaccessible to non-morphologists, and causes phenomics to lag behind genomics in elucidating evolutionary patterns. Unlike other algorithms presented for morphological correspondences our approach does not require any preliminary marking of special features or landmarks by the user. It also differs from other seminal work in computational geometry in that our algorithms are polynomial in nature and thus faster, making pairwise comparisons feasible for significantly larger numbers of digitized surfaces. We illustrate our approach using three datasets representing teeth and different bones of primates and humans, and show that it leads to highly accurate results.Comment: Changes with respect to v1, v2: an Erratum was added, correcting the references for one of the three datasets. Note that the datasets and code for this paper can be obtained from the Data Conservancy (see Download column on v1, v2

    Probable changes in lake chemistry in Canada's Atlantic Provinces under proposed North American emission reductions

    No full text
    International audienceAtlantic Canada, located in the extreme north-eastern portion of North America, receives acid precipitation from all major acid emission sources on the eastern part of the continent. The region was glaciated and has thin soils over a generally poorly acid buffering bedrock. Because of regional topography, large groupings of lakes occur in a number of regions. Environment Canada and the Government of New Brunswick have operated lake sampling networks in trend detection studies and have concentrated their work on these lake groupings. The MAGIC model has been applied to these lakes and their catchments to see: a) what initial water chemistry conditions existed before acidification began, b) what the chemistry was like during the worst of regional acid deposition, and c) what it would be like under deposition conditions predicted for new Canadian and US emission reduction proposals. While pH, sulphate, acid neutralisation capacity (ANC) and the sum of the base cations (SBC) of all lakes have been significantly affected by acid deposition, water chemistry conditions are now considerably better than they were in 1975, at the worst of the deposition. However, a 50% reduction in acid deposition from Year 2000 deposition amounts will not return water chemistry to original conditions in most of the region. Keywords: Atlantic Canada, monitoring networks, acidification, predictions, MAGI

    The joint influence of gender and amount of smoking on weight gain one year after smoking cessation.

    Get PDF
    Weight gain is often associated with smoking cessation and may discourage smokers from quitting. This study estimated the weight gained one year after smoking cessation and examined the risk factors associated with weight gain in order to identify socio-demographic groups at higher risk of increased weight after quitting. We analyzed data from 750 adults in two randomized controlled studies that included smokers motivated to quit and found a gradient in weight gain according to the actual duration of abstinence during follow-up. Subjects who were abstinent for at least 40 weeks gained 4.6 kg (SD = 3.8) on average, compared to 1.2 kg (SD = 2.6) for those who were abstinent less than 20 weeks during the 1-year follow-up. Considering the duration of abstinence as an exposure variable, we found an age effect and a significant interaction between sex and the amount of smoking before quitting: younger subjects gained more weight than older subjects; among light smokers, men gained more weight on average than women one year after quitting, while the opposite was observed among heavy smokers. Young women smoking heavily at baseline had the highest risk of weight gain after quitting

    Age-related decrements in cycling and running performance

    Get PDF
    Objective. This study examined age-related decrements in athletic performance during running and cycling activities. Design. The age group winning times for males aged between 18 and 70 years competing in the 1999 Argus cycle tour (103 km) and 1999 Comrades running marathon (90 km), South Africa's premier endurance cycling and running events respectively, were examined. Main outcome measures. The relationship between speed (cycling and running respectively) and age was calculated using a 4th order polynomial function. The derivative of each of these functions was determined and then the slope of the function corresponding to each age was calculated. Results. The rate of decline in running speed occurred at an earlier age (~ 32 years) during the running race compared with the cycling tour (~ 55 years). Conclusions. These findings establish a trend that there is ‘accelerated' aging during running which can perhaps be attributed to the increased weight-bearing stress on the muscles during running compared with cycling

    Stable Isotope Dynamics in Cownose Rays (Rhinoptera bonasus) within the Northwestern Gulf of Mexico

    Get PDF
    The cownose ray (Rhinoptera bonasus) is a durophagous mesopredator that exerts for top-down control on commercial shellfish stocks along the Atlantic coast. Although the trophic ecology of this elasmobranch has been the subject of extensive investigation, there is limited information available on feeding patterns of cownose rays in the northwestern Gulf of Mexico. Stable isotope analysis has been used to study the foraging ecology of various species, but only recently applied to elasmobranchs. Therefore, this study conducted a controlled feeding trial to determine incorporation rates and diet-tissue discrimination factors for δ^(13)C and δ^(15)N in cownose ray epidermal tissue. Additionally, this study investigates δ^(13)C and δ^(15)N variability in cownose rays captured via entanglement nets, from surveys along the Texas coast from 2009 – 2012. This is the first study to report δ^(13)C and δ^(15)N incorporation rates in elasmobranch epidermal tissue; estimated δ^(13)C and δ^(15)N incorporation rates were 0.0018 ± 0.0003 days^(-1) and 0.0059 ± 0.0022 days^(-1), respectively. Isotopic incorporation rates were highly variable amongst individuals but did not vary significantly with ray size (disc width or weight). Isotopic equilibrium was not reached between the epidermal tissue and the dietary treatment levels; therefore, estimated diet-tissue discrimination factors (Δ^(13)C = 4.26‰ and Δ^(15)N = 0.69‰) could not be applied for analyses of wild populations. Relative size of Bayesian ellipses, denoting the isotopic niche of cownose rays, varied seasonally in the lower Laguna Madre, with Summer 2012 significantly smaller than all other sampling periods. Female mean δ^(13)C signatures were significantly enriched compared to those of males, indicating that female rays are foraging over longer periods of time within inshore habitats. Isotopic niche size was comparable across the Texas bay systems in 2012, with only the lower Laguna Madre (Spring) significantly smaller. However, mean δ^(13)C and δ^(15)N in cownose rays varied spatially across bay systems along the Texas coast. This initial exploration into the trophic ecology of cownose rays within the northwestern Gulf of Mexico provides evidence of temporal and spatial variability in isotopic signatures, potentially aiding scientists in the management of this species

    Leptin and smoking cessation: secondary analyses of a randomized controlled trial assessing physical activity as an aid for smoking cessation.

    Get PDF
    BACKGROUND: Smokers have a lower body weight compared to non-smokers. Smoking cessation is associated with weight gain in most cases. A hormonal mechanism of action might be implicated in weight variations related to smoking, and leptin might be implicated. We made secondary analyses of an RCT, with a hypothesis-free exploratory approach to study the dynamic of leptin following smoking cessation. METHODS: We measured serum leptin levels among 271 sedentary smokers willing to quit who participated in a randomized controlled trial assessing a 9-week moderate-intensity physical activity intervention as an aid for smoking cessation. We adjusted leptin for body fat levels. We performed linear regressions to test for an association between leptin levels and the study group over time. RESULTS: One year after smoking cessation, the mean serum leptin change was +3.23 mg/l (SD 4.89) in the control group and +1.25 mg/l (SD 4.86) in the intervention group (p of the difference < 0.05). When adjusted for body fat levels, leptin was higher in the control group than in the intervention group (p of the difference < 0.01). The mean weight gain was +2.91 (SD 6.66) Kg in the intervention and +3.33 (SD 4.47) Kg in the control groups, respectively (p not significant). CONCLUSIONS: Serum leptin levels significantly increased after smoking cessation, in spite of substantial weight gain. The leptin dynamic might be different in chronic tobacco users who quit smoking, and physical activity might impact the dynamic of leptin in such a situation. CLINICAL TRIAL REGISTRATION NUMBER: NCT00521391

    Group A streptococcal vaccine delivery by immunization with a self-adjuvanting M protein-based lipid core peptide construct

    Get PDF
    Background & objectives: To develop a broad strain coverage GAS vaccine, several strategies have been investigated which included multi-epitope approaches as well as targeting the M protein conserved C-region. These approaches, however, have relied on the use of adjuvants that are toxic for human application. The development of safe and effective adjuvants for human use is a key issue in the development of effective vaccines. In this study, we investigated the lipid polylysine core peptide (LCP) system as a self-adjuvanting GAS vaccine delivery approach. Methods: An LCP-GAS construct was synthesised incorporating multiple copies of a protective peptide epitope (J8) from the conserved carboxy terminal C-repeat region of the M protein. B10.BR mice were immunized parenterally with the LCP-J8 construct, with or without conventional adjuvant, prior to the assessment of immunogenicity and the induction of serum opsonic antibodies. Results: Our data demonstrated immunogenicity of LCP-J8 when coadministered in complete Freund's adjuvant (CFA), or administered in the absence of conventional adjuvant. In both cases, immunization led to the induction of high-titre J8 peptide-specific serum IgG antibody responses, and the induction of heterologous opsonic antibodies that did not cross-react with human heart tissue proteins. Interpretation & conclusion: These data indicated the potential of a novel self-adjuvanting LCP vaccine delivery system incorporating a synthetic GAS M protein C-region peptide immunogen in the induction of broadly protective immune responses, and pointed to the potential application of this system in human vaccine development against infectious diseases

    Knowledge of AIDS and HIV transmission among drug users in Rio de Janeiro, Brazil

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Proper knowledge of HIV transmission is not enough for people to adopt protective behaviors, but deficits in this information may increase HIV/AIDS vulnerability.</p> <p>Objective</p> <p>To assess drug users' knowledge of HIV/AIDS and the possible association between knowledge and HIV testing.</p> <p>Methods</p> <p>A Cross-sectional study conducted in 2006/7 with a convenience sample of 295 illicit drug users in Rio de Janeiro, assessing knowledge on AIDS/HIV transmission and its relationship with HIV testing. Information from 108 randomly selected drug users who received an educational intervention using cards illustrating situations potentially associated with HIV transmission were assessed using Multidimensional Scaling (MDS).</p> <p>Results</p> <p>Almost 40% of drug users reported having never used condoms and more than 60% reported not using condoms under the influence of substances. Most drug users (80.6%) correctly answered that condoms make sex safer, but incorrect beliefs are still common (e.g. nearly 44% believed HIV can be transmitted through saliva and 55% reported that HIV infection can be transmitted by sharing toothbrushes), with significant differences between drug users who had and who had not been tested for HIV. MDS showed queries on vaginal/anal sex and sharing syringes/needles were classified in the same set as effective modes of HIV transmission. The event that was further away from this core of properly perceived risks referred to blood donation, perceived as risky. Other items were found to be dispersed, suggesting inchoate beliefs on transmission modes.</p> <p>Conclusions</p> <p>Drug users have an increased HIV infection vulnerability compared to the general population, this specific population expressed relevant doubts about HIV transmission, as well as high levels of risky behavior. Moreover, the findings suggest that possessing inaccurate HIV/AIDS knowledge may be a barrier to timely HIV testing. Interventions should be tailored to such specific characteristics.</p
    corecore